ABSTRACT
This chapter aims to provide some background to how thinking on security, war and defence is changing as a result of the attacks on America. It does this by examining traditional notions of security and war, before going on to assess the impact of September 11 on the nature of war, defence strategies, and global politics more generally. Terrorists also do not operate in accordance with the norms and customs of conventional warfare, or even pretend to recognize laws of war. The nature of warfare and security threats is changing in radical ways. Since the demise of the Cold War perceptions of threats and who represent the main adversaries has altered fundamentally. The tendency for the US to act independently of its European allies to a much greater extent than hitherto is causing anxiety in European capitals.
